They found that when a person becomes happy, a friend living close by has a 25 percent higher chance of becoming happy themselves. A spouse experiences an 8 percent increased chance and for next-door neighbors, it’s 34 percent.

“Everyday interactions we have with other people are definitely contagious, in terms of happiness,” says Nicholas Christakis, a professor at Harvard Medical School and an author of the study.

I must admit, it’s somewhat disconcerting that the happiness correlations seems so low for spouses but this speaks to the significance of becoming the good we hope to see in the world. It starts very close to home in our everyday interactions. In fact, according to this study, happiness is much more contagious than unhappiness is. Perhaps we are hardwired to seek out joy?

Another intriguing result of this study:

Perhaps more surprising, Christakis says, is that the effect extends beyond the people we come into contact with. When one person becomes happy, the social network effect can spread up to 3 degrees — reaching friends of friends.

So, Facebook friends, keep on giving us those status updates about how good that cheeseburger was yesterday and about your favorite songs — it’s good for the rest of us :)